Mobile communication devices have become increasingly common in current society for providing wireless communication services. The prevalence of these mobile communication devices is driven in part by the many functions that are now enabled on such devices. Increased processing capabilities in such devices means that mobile communication devices have evolved from being pure communication tools into sophisticated mobile multimedia centers that enable enhanced user experiences.
The redefined user experience requires higher data rates offered by wireless communication technologies, such as fifth generation new radio (5G-NR) and Wi-Fi that typically operates in higher frequency spectrums. To achieve higher data rates with increased robustness in the higher frequency spectrums, the mobile communication devices may employ multiple antennas to enable multiple-input multiple-output (MIMO) and/or beamforming operations. Sophisticated power amplifiers (PAs) may be employed to increase output power of radio frequency (RF) signals (e.g., maintaining sufficient energy per bit) prior to transmitting the RF signals from the multiple antennas. However, the increased number of antennas and PAs can lead to increased power dissipation in the mobile communication devices, thus compromising overall performance and user experiences.
Envelope tracking is a power management technology designed to improve efficiency levels of the PAs to help reduce power dissipation in the mobile communication devices. As the name suggests, an envelope tracking system keeps track of an amplitude envelope of the RF signals communicated by the mobile communication devices. The envelope tracking system constantly adjusts supply voltages applied to the PAs to ensure that the PAs are operating at a higher linearity and efficiency for a given instantaneous output power requirement of the RF signals. Notably, the real estate of a mobile communication device has become increasingly precious as more and more antennas, PAs, and/or envelope tracking circuits are packed into the envelope tracking system. As such, it may be necessary to maintain or even reduce footprint of the envelope tracking system without compromising performance of mobile communication device.